The Laozhaiwan gold deposit is located in southeast of Yunnan Province, within the famous "Golden Triangle in Yunnan, Guizhou and Guangxi". So far it is the unique "Carlin type" gold deposit that has been surveyed in detail and exploited on a large scale. At present it has been determined that this deposit is of intermediate-large size, and constructed into the first gold mine of ton-level in Yunnan Province, exhibiting good mineralization conditions and ore-search prospect. In this paper, the authors analyze the geological setting, geological characteristics, geochemistry and ore features of this deposit. The authors suggest that its genesis is associated with hydrothermal reformation in the later period, and it is a micro-fine grain gold deposit of the sedimentary type.